The California Department of Water Resources (DWR) will receive $9.25 million toward funding for research into atmospheric rivers in the California Legislature’s 2019-’20 budget.
A coalition of California water agencies that included the Orange County Water District (OCWD), Sonoma Water, San Diego County Water Authority, Turlock Water and Power, Yuba Water Agency, and the Association of California Water Agencies (ACWA), was developed in 2018 to gain state funding for research to improve observations, forecasts and decision support of atmospheric river (AR) precipitation events in California. The appropriation, sponsored by Senator Bill Dodd (D-Napa) and Assemblymember Jim Wood (DSanta Rosa), will fund the Atmospheric Rivers: Research, Mitigation, and Climate Forecasting Program (AR Program) at DWR.
Atmospheric rivers provide 30-50% of California’s annual precipitation and cause 90% of the flood events throughout the state. “Sonoma Water is pleased to have joined this coalition to support critical state funding to accelerate atmospheric river research and improved decision-making tools such as Forecast Informed Reservoir Operations (FIRO). This funding will enable water managers to more accurately track, monitor and respond to major storm events, such as the flooding that took place in Sonoma County earlier this year,” said
Grant Davis, general manager of Sonoma Water.
The coalition is working with the Center for Western Weather and Water Extremes at the Scripps Institution of Oceanography at University California, San Diego to study atmospheric rivers to improve forecasting of these all-important storm events. This work has been supported by an early investment of $3 million appropriated by the California Legislature three years ago in the 2016-’17 budget to study atmospheric rivers.
This additional funding will further atmospheric river science and improve forecasting tools. Enhanced forecasting of atmospheric rivers will support FIRO which allows reservoir operators and water suppliers to better predict how much precipitation from atmospheric rivers can be retained in reservoirs, thus enabling more efficient capture and use of stormwater. FIRO refers to a proposed management strategy to use modern weather forecasting, runoff modeling and watershed monitoring to help water managers selectively
retain or release water from reservoirs in a manner that reflects current and forecasted conditions.
“The legislative leadership demonstrated on this issue is essential to ensuring a better understanding of atmospheric river patterns, which could potentially inform the Water Authority and its member agencies of new reservoir operations opportunities to improve water capture and flood protection throughout the San Diego region,” said Sandra Kerl, acting general manager of the San Diego County Water Authority.
This has implications for reservoirs operated around the state, including Oroville and Prado Dam. “The Orange County Water District is grateful to Senator Dodd and Assemblymember Wood for their efforts in securing funding for FIRO research,” stated Vicente Sarmiento, president of OCWD. “With better weather forecasting, an additional 20,000 acre-feet of storage space could be made available for stormwater capture behind Prado Dam without impacting flood risk. Doing so would allow OCWD to capture and use an additional 20,000 acrefeet or 6.5 billion gallons of stormwater in a wet year which would otherwise drain to the Pacific Ocean. That’s enough water for 160,000 people.”
“This essential investment in public safety and sustainable water management shows true leadership and is vitally important as California works to address the challenges of climate change,” said Curt Aikens, general manager of Yuba Water Agency.
Scripps and the coalition have also embarked on a multi-phase federal scoping study in collaboration with the U.S. Army Corps of Engineers to assess the viability of using FIRO for reservoirs in the southwest United States, where the majority of rainfall often occurs in three to four storms per year.
Many members of the coalition have worked to optimize the amount of water stored behind reservoirs and dams to recharge as much of the limited rainfall as possible into groundwater basins and reservoirs. Large rainfall events caused by atmospheric rivers are a major source of water supply in Southern California.